summaryrefslogtreecommitdiff
path: root/drivers/net/dsa/b53/b53_spi.c
blob: 2bda0b5f15787ae1892255c70b84b6dfa25980b3 (plain) (blame)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
/*
 * B53 register access through SPI
 *
 * Copyright (C) 2011-2013 Jonas Gorski <jogo@openwrt.org>
 *
 * Permission to use, copy, modify, and/or distribute this software for any
 * purpose with or without fee is hereby granted, provided that the above
 * copyright notice and this permission notice appear in all copies.
 *
 * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
 * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
 * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
 * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
 * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
 * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
 * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
 */

#include <asm/unaligned.h>

#include <linux/delay.h>
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/spi/spi.h>
#include <linux/platform_data/b53.h>

#include "b53_priv.h"

#define B53_SPI_DATA		0xf0

#define B53_SPI_STATUS		0xfe
#define B53_SPI_CMD_SPIF	BIT(7)
#define B53_SPI_CMD_RACK	BIT(5)

#define B53_SPI_CMD_READ	0x00
#define B53_SPI_CMD_WRITE	0x01
#define B53_SPI_CMD_NORMAL	0x60
#define B53_SPI_CMD_FAST	0x10

#define B53_SPI_PAGE_SELECT	0xff

static inline int b53_spi_read_reg(struct spi_device *spi, u8 reg, u8 *val,
				   unsigned int len)
{
	u8 txbuf[2];

	txbuf[0] = B53_SPI_CMD_NORMAL | B53_SPI_CMD_READ;
	txbuf[1] = reg;

	return spi_write_then_read(spi, txbuf, 2, val, len);
}

static inline int b53_spi_clear_status(struct spi_device *spi)
{
	unsigned int i;
	u8 rxbuf;
	int ret;

	for (i = 0; i < 10; i++) {
		ret = b53_spi_read_reg(spi, B53_SPI_STATUS, &rxbuf, 1);
		if (ret)
			return ret;

		if (!(rxbuf & B53_SPI_CMD_SPIF))
			break;

		mdelay(1);
	}

	if (i == 10)
		return -EIO;

	return 0;
}

static inline int b53_spi_set_page(struct spi_device *spi, u8 page)
{
	u8 txbuf[3];

	txbuf[0] = B53_SPI_CMD_NORMAL | B53_SPI_CMD_WRITE;
	txbuf[1] = B53_SPI_PAGE_SELECT;
	txbuf[2] = page;

	return spi_write(spi, txbuf, sizeof(txbuf));
}

static inline int b53_prepare_reg_access(struct spi_device *spi, u8 page)
{
	int ret = b53_spi_clear_status(spi);

	if (ret)
		return ret;

	return b53_spi_set_page(spi, page);
}

static int b53_spi_prepare_reg_read(struct spi_device *spi, u8 reg)
{
	u8 rxbuf;
	int retry_count;
	int ret;

	ret = b53_spi_read_reg(spi, reg, &rxbuf, 1);
	if (ret)
		return ret;

	for (retry_count = 0; retry_count < 10; retry_count++) {
		ret = b53_spi_read_reg(spi, B53_SPI_STATUS, &rxbuf, 1);
		if (ret)
			return ret;

		if (rxbuf & B53_SPI_CMD_RACK)
			break;

		mdelay(1);
	}

	if (retry_count == 10)
		return -EIO;

	return 0;
}

static int b53_spi_read(struct b53_device *dev, u8 page, u8 reg, u8 *data,
			unsigned int len)
{
	struct spi_device *spi = dev->priv;
	int ret;

	ret = b53_prepare_reg_access(spi, page);
	if (ret)
		return ret;

	ret = b53_spi_prepare_reg_read(spi, reg);
	if (ret)
		return ret;

	return b53_spi_read_reg(spi, B53_SPI_DATA, data, len);
}

static int b53_spi_read8(struct b53_device *dev, u8 page, u8 reg, u8 *val)
{
	return b53_spi_read(dev, page, reg, val, 1);
}

static int b53_spi_read16(struct b53_device *dev, u8 page, u8 reg, u16 *val)
{
	int ret = b53_spi_read(dev, page, reg, (u8 *)val, 2);

	if (!ret)
		*val = le16_to_cpu(*val);

	return ret;
}

static int b53_spi_read32(struct b53_device *dev, u8 page, u8 reg, u32 *val)
{
	int ret = b53_spi_read(dev, page, reg, (u8 *)val, 4);

	if (!ret)
		*val = le32_to_cpu(*val);

	return ret;
}

static int b53_spi_read48(struct b53_device *dev, u8 page, u8 reg, u64 *val)
{
	int ret;

	*val = 0;
	ret = b53_spi_read(dev, page, reg, (u8 *)val, 6);
	if (!ret)
		*val = le64_to_cpu(*val);

	return ret;
}

static int b53_spi_read64(struct b53_device *dev, u8 page, u8 reg, u64 *val)
{
	int ret = b53_spi_read(dev, page, reg, (u8 *)val, 8);

	if (!ret)
		*val = le64_to_cpu(*val);

	return ret;
}

static int b53_spi_write8(struct b53_device *dev, u8 page, u8 reg, u8 value)
{
	struct spi_device *spi = dev->priv;
	int ret;
	u8 txbuf[3];

	ret = b53_prepare_reg_access(spi, page);
	if (ret)
		return ret;

	txbuf[0] = B53_SPI_CMD_NORMAL | B53_SPI_CMD_WRITE;
	txbuf[1] = reg;
	txbuf[2] = value;

	return spi_write(spi, txbuf, sizeof(txbuf));
}

static int b53_spi_write16(struct b53_device *dev, u8 page, u8 reg, u16 value)
{
	struct spi_device *spi = dev->priv;
	int ret;
	u8 txbuf[4];

	ret = b53_prepare_reg_access(spi, page);
	if (ret)
		return ret;

	txbuf[0] = B53_SPI_CMD_NORMAL | B53_SPI_CMD_WRITE;
	txbuf[1] = reg;
	put_unaligned_le16(value, &txbuf[2]);

	return spi_write(spi, txbuf, sizeof(txbuf));
}

static int b53_spi_write32(struct b53_device *dev, u8 page, u8 reg, u32 value)
{
	struct spi_device *spi = dev->priv;
	int ret;
	u8 txbuf[6];

	ret = b53_prepare_reg_access(spi, page);
	if (ret)
		return ret;

	txbuf[0] = B53_SPI_CMD_NORMAL | B53_SPI_CMD_WRITE;
	txbuf[1] = reg;
	put_unaligned_le32(value, &txbuf[2]);

	return spi_write(spi, txbuf, sizeof(txbuf));
}

static int b53_spi_write48(struct b53_device *dev, u8 page, u8 reg, u64 value)
{
	struct spi_device *spi = dev->priv;
	int ret;
	u8 txbuf[10];

	ret = b53_prepare_reg_access(spi, page);
	if (ret)
		return ret;

	txbuf[0] = B53_SPI_CMD_NORMAL | B53_SPI_CMD_WRITE;
	txbuf[1] = reg;
	put_unaligned_le64(value, &txbuf[2]);

	return spi_write(spi, txbuf, sizeof(txbuf) - 2);
}

static int b53_spi_write64(struct b53_device *dev, u8 page, u8 reg, u64 value)
{
	struct spi_device *spi = dev->priv;
	int ret;
	u8 txbuf[10];

	ret = b53_prepare_reg_access(spi, page);
	if (ret)
		return ret;

	txbuf[0] = B53_SPI_CMD_NORMAL | B53_SPI_CMD_WRITE;
	txbuf[1] = reg;
	put_unaligned_le64(value, &txbuf[2]);

	return spi_write(spi, txbuf, sizeof(txbuf));
}

static struct b53_io_ops b53_spi_ops = {
	.read8 = b53_spi_read8,
	.read16 = b53_spi_read16,
	.read32 = b53_spi_read32,
	.read48 = b53_spi_read48,
	.read64 = b53_spi_read64,
	.write8 = b53_spi_write8,
	.write16 = b53_spi_write16,
	.write32 = b53_spi_write32,
	.write48 = b53_spi_write48,
	.write64 = b53_spi_write64,
};

static int b53_spi_probe(struct spi_device *spi)
{
	struct b53_device *dev;
	int ret;

	dev = b53_switch_alloc(&spi->dev, &b53_spi_ops, spi);
	if (!dev)
		return -ENOMEM;

	if (spi->dev.platform_data)
		dev->pdata = spi->dev.platform_data;

	ret = b53_switch_register(dev);
	if (ret)
		return ret;

	spi_set_drvdata(spi, dev);

	return 0;
}

static int b53_spi_remove(struct spi_device *spi)
{
	struct b53_device *dev = spi_get_drvdata(spi);

	if (dev)
		b53_switch_remove(dev);

	return 0;
}

static struct spi_driver b53_spi_driver = {
	.driver = {
		.name	= "b53-switch",
		.bus	= &spi_bus_type,
		.owner	= THIS_MODULE,
	},
	.probe	= b53_spi_probe,
	.remove	= b53_spi_remove,
};

module_spi_driver(b53_spi_driver);

MODULE_AUTHOR("Jonas Gorski <jogo@openwrt.org>");
MODULE_DESCRIPTION("B53 SPI access driver");
MODULE_LICENSE("Dual BSD/GPL");